High level competition is demanding on both horse and rider and inevitably over time takes its toll in injury and wear and tear; this said, with careful professional support it is possible to maintain an athlete in work and overcome these obstacles to complete a full career.
Discussion of diminished performance with your farrier may reveal uneven shoe wear, a distorted hoof or less flexibility. Conformation determines gait, which affects shoe/hoof wear, which in turn dictates the hoof trimming and shoeing strategy. Shoe wear highlights amongst other things balance or imbalance, and impaired flexion.
The farrier will trim and shoe to achieve level foot fall, with a central base for the loaded limb. The vet is often not consulted until the horse is lame, when specific areas may be x-rayed for bone changes and to identify foot/limb imbalance.
Lateral rotation of one or more joints of the limb commonly from the knee, is a common problem recognised by seeing it move outward when flexed. As the foot lands it makes ground contact on the lateral side first, then loads the inside heel quarter, when going through the weight bearing stage of the stride. This conformation may not be obvious when the horse is standing. The shoe wear will be heavier on the outside and toe quarter.